In general, a test handler is an apparatus for assisting semiconductor devices manufactured by a desired manufacturing process to be tested and for classifying the semiconductor devices by a grade according to a test result to load the same in customer trays, and is already disclosed in various published documents.
FIG. 1 is a schematic view illustrating a conventional test handler, and the conventional test handler will be described briefly with reference to FIG. 1 as follows.
As illustrated in FIG. 1, the conventional test handler includes a loading apparatus 110, a soak chamber 120, a test chamber 130, a de-soak chamber 140, and an unloading apparatus 150.
The loading apparatus 110 loads the semiconductor devices accommodated in the customer trays assigned by a reference numeral 101a into a horizontal test tray at a loading position.
The soak chamber 120 is provided to accommodate the loaded test trays sequentially and preheat and pre-cool the semiconductor devices loaded in the test trays. To this end, in the soak chamber 120, a desired temperature is made for the preheating and pre-cooling of the semiconductor devices.
The test chamber 130 is provided to directly assist the test of the semiconductor devices loaded in the test trays which are supplied from the soak chamber 120. To this end, the test chamber 130 includes a mechanical structure for contacting the semiconductor devices loaded in the test trays with test sockets of a tester.
The de-soak chamber 140 is provided to remove heat or chill from hot or cold semiconductor devices.
The unloading apparatus 150 classifies the tested semiconductor devices loaded in the test trays at an unloading position and unloads the same to customer trays assigned by a reference numeral 101b. 
Although, in the test handler of FIG. 1, the loading apparatus 110 and the unloading apparatus 150 are separated from each other, if the loading and the unloading are carried out at the same position, a single loading and unloading apparatus may be implemented to perform both of the unloading and the loading.
Meanwhile, currently there are several types of the test handler which are classified in the way that the test trays contact the tester, such as an under head docking type test handler (a way that the test trays contact the test in a horizontal state) and a side docking type test handler (a way that the test trays contact the test in a vertical state), and the test handler as illustrated in FIG. 1 relates to the side docking type test handler. As such, the side docking type test handler needs a posture changing apparatus for changing the posture of the test trays from the horizontal state to the vertical state or vice versa. A reference numeral 160 in FIG. 1 is assigned to a vertical posture changing apparatus for changing the horizontal state of the test tray, the loading of which is finished, into the vertical state and a reference numeral 170 in FIG. 1 is a horizontal posture changing apparatus for changing the vertical state of test tray having the tested semiconductor devices into the horizontal state. In case that changing the posture into the horizontal state and changing the posture into the vertical state are constituted at the same position, the vertical posture changing apparatus and the horizontal posture changing apparatus can be implemented by a single apparatus.
FIGS. 2 and 3 are conceptual plan views of the test handler in FIG. 1.
In FIG. 2, a transferring direction ‘a’ of the test trays and a transferring direction ‘b’ of the semiconductor devices in the test handler in FIG. 1 are depicted.
As illustrated in FIG. 3, the test chamber 130 includes a test stand-by unit 131, a test unit 132, and an output stand-by unit 133. In the test stand-by unit 131, the test trays, transferred from the soak chamber 120, stand by to be transferred to the test unit 132. In the test unit 132, the semiconductor devices loaded in the test trays which are transferred from the test stand-by unit 131 are tested, and in the output stand-by unit 133, the test trays having the semiconductor devices tested in the test unit 132, stand by to be outputted to the de-soak chamber 140. In the test chamber 130, the test trays, firstly, are transferred from the test stand-by unit 131 to the test unit 132, and secondly, are transferred from the test unit 132 to the output stand-by unit 133. In this case, according to the related art, the first transferring is carried out by a first test tray transferring apparatus. And the second transferring is carried out over two steps. The test trays in the test unit 132 are pushed by some distance near to the output stand-by unit 133 by the test trays transferred from the test stand-by unit 131 to the test unit 132 according to the first transferring and then, are completely transferred to the output stand-by unit 133 by a second test tray transferring apparatus. For reference, the conventional test tray transferring apparatus is disclosed in Korean Patent Published No. 10-2004-0092786 (entitled ‘Test Tray Transferring Apparatus for Semiconductor Device Test Handler’) and Korean Patent Published No. 10-2007-0063903 (entitled ‘Test Handler’, hereinafter referred to ‘Related art’) filed by this applicant, and FIG. 4 schematically illustrates an application of a test tray transferring apparatus 180 according to the related art.
However, if the first transferring and the second transferring are carried out by a single test tray transferring apparatus 180, the second transferring must be carried out by the test tray transferring apparatus 180 after the first transferring has been performed by the test tray transferring apparatus 180. In this case, during the second transferring, an action of pushing the test trays transferred to the test unit 132 to the tester cannot be carried out. This is because there occurs interference between the test tray transferring apparatus 180 for performing the second transferring and a pushing unit 190 for pushing the test trays to the tester. Thus, since, in this case, the flow of the test trays becomes slow within the test chamber, two test tray transferring apparatuses must be provided.
Moreover, since the second transferring is started by the collision between the test trays, the test trays and the semiconductor devices loaded therein are possibly damaged. Since the second test tray transferring apparatus for completing the second transferring must be provided, two expensive motors must be installed.